Hydrocarbon conversion



Dec. 7, 1943. D. READ, JR

HYDROCARBON CONVERSION Filed April 29, 1940 IEZIE/VER Patented Dec. 7,1943 v u UNITED ,STATES PATENT OFFICE i UA mnocAanoN comasroN assumes-,-

am: poration oi' Delaware Application April 2s, 1940. serial No. 332,136

-. 7 claims. l'cl. iss-sz) This invention relates to a process forconhydrocarbon oil and spent catalyst while' the verting relatively wideboiling range hydrocarsecond part consists of lighter oils andrelatlvebon oils into high yields of high anti-knock gasoly clean catalyst zwithprovisions for recovering line and more Speciiically it is concernedwith Ithe rst part and returning the second part to an improvement inthe art ior cracking hydrocarthe catalytic conversion step.

bon oil wherein a relatively heavy hydrocarbon In one specificembodiment the invention coinoil is non-catalytically cracked and therelativeprises subjecting a relatively heavy hydrocarbon ly lighthydrocarbon oil catalytically cracked in oil to pyrolytic cracking in aheating coil and the presence of a catalyst suspended therein.communicating reaction Chamber, Separatin The improvement principallyinvolves quenching 10 non-vaporous liquid residue from thepyrolyticalthe stream of hydrocarbon oils containing the ly i'ormedvaporous conversion products, simulsuspended catalyst as it leaves thereaction zone taneously therewith commingling a slurry of to arrest thecracking reaction whereby to recracking catalyst with a relatively lighthydroduce to a minimum the formation oi' carbonacecarbon oil and passingthe mixture through a ous andresidual materials. reaction zone where itis heated to a catalytic I have i'ound that in the catalytic cracking ofcracking temperature. quenching the heated y hydrocarbon oil in thepresence of a catalyst susstream oi' hydrocarbon oil and `catalystleaving pended therein, the reaction is usually accomthe reaction zoneto arrest the cracking reacplished at high temperatures, and if thecatalyst tion, Separating the catalyst and heavy Catis allowed to remainin contact with the oil lytic residue from the catalytically formedvaafter the desired reaction is accomplished, unusuporous Conversionproducts, further separating ally high amounts of carbonaceous materialsare the mixture of catalytic residue and catalyst into formed which aredeposited with the catalyst in two parts, one part consistingessentially of the the separating zone. Residual materials formedheavier portion oi the catalytic residue and spent in these reactionsare usually` of such a nature catalyst and the second part consisting ofrelathat they are more carbonaceous than hydrotively light catalyticresidue and relatively clean carbonaceous, and hence are not readilysoluble catalyst, recovering the ilrst part and returninhydrocarbonsolvents. Hycimcarbonaceous ing the second prt to the catalyticconversion materials, on the other hand, usually exist as a step,commingling said catalytically formed valiquid, such as the heavyresidual oils which are porous conversion products with saidpyrolyticalseparated from the conversion products along ly formedvaporous conversion products and with the catalyst, and being soluble inmost hyfractionating the mixture. together with the drocarbon solvents,may be removed from the charging oil, to substantially separatefractioncatalyst by either settling or by washing the catated vaporsboiling in the range oi.' gasoline from alyst with a suitable solvent.the higher boiling conversion products and heav- In view of the above,my invention provides for ier portions ot'the charging oil, recoveringsaid quenching the stream of hydrocarbon oil confractionatedI vapors,condensing said higher boiltaining the suspended catalyst as it leavesthe reing conversion products and said heavier poraction zone to reducethe temperature thereof to 40' tions of the charging oil as light andheavy a temperature below that at which cracking is reilux condensates,supplying said heavy reilux eil'eeted, after which the mixtureissupplied to a condensate to the pyrolytic conversion step asvaporizing and separating chamber wherein vasaid relatively heavy oil.,and supplying said light porous conversion products are substantiallyretluxcondensate to the catalytic conversion step separated from theheavier hydrocarbon oils and as said relatively light hydrocarbon oil.catalyst. Additional provisions are made for ini The accompanyingdiagrammatic drawing iltroducing a stream of cooling oil to thevaporizlustrates in conventional side elevation one speing andseparating chamber in order to control cinc form of the apparatus whichmay be enlthe end point of the vaporous conversion prodployedtoaccomplish the objects oi the invenucts and the viscosity and gravityoi' the hydro- 6o tion. carbon oils removed with the catalyst. The in-Referring nowto the drawing, heavy reilux convention also provides forsupplying the mixture densate formed in the manner to be described ofcatalyst and-oil to a catalyst separating chamlater is suplied toheating coil I. 'I'he heavy reber whereinA the mixture is separated intotwo ux condensate in passing through heating coil parts. one partconsisting essentially ot the heavy i is raised to the desiredconversion temperature which may range, for example, from 850 to 1000F., or more, by means of heat supplied from furnace 2. The heavy refluxcondensate leaving heating coil I at an outlet pressure ranging, forexample, from 100 to 500 pounds or more per square inch is directedthrough line 3 and valve 4 into reaction chamber 6. Reaction chamber 5is preferably maintained at substantially the same pressure or at aslightly lower pressure than that employed on the outlet of heating coilI and is preferably insulated to reduce radiation losses therefrom,although no insulation is shown in the drawing.

The heated reflux condensate in passing through reaction chamber 5 issubjected to prolonged pyrolytic conversion at the elevated temperatureand the resulting conversion products are discharged therefrom throughline 8 and valve 1 into vaporizing and separating chamber 8.Vaporizingand separating chamber 8 is preferably maintained at a reducedpressure relative to that employed in reaction chamber B ranging, forexample, from substantially atmospheric to 400 pounds or more per squareinch in order to obtain a separation between the vaporous and liquidconversion products and to effect substantial further vaporization ofthe liquid conversion products to form a non-vaporous liquid residue.Non-vaporous liquid residue separated in chamber 8 is removed therefromby way of line 9 and 'valve IIJ and may be recovered as a product of theprocess or subjected to any desired further treatment. Vaporousconversion products, together with vapors evolved within chamber 8, aredirected through line II and valve l2 into fractionator I3 for treatmentin the mannerI to be described later.

Simultaneously with the pyrolytic conversion treatment of the heavyreflux condensate as above described, light reflux condensate to whichpowdered catalyst'is added in the manner to be described later, issupplied to heating coil I4. The slurry of catalyst and oil in passingthrough heating coil I4 is raised to the desired conversion temperatureranging, for example, from 500 to 1200 F., heat being supplied by meansof fur-, nace I5. Preferably also, heat is supplied to the slurry ofcatalyst and oil in heating coil I4 at a rapid rate so as to minimizethe amount of pyrolytic cracking effected and increase the amount ofcatalytic cracking. When desired, a reaction zone other than a heatingcoil may be employed, however, in view of the fact that control of theheating is more readily obtained in a heating coil than in other typesof reaction vessels the method illustrated is the preferred method.

The heated mixture of oil and catalyst leaving heating coil I4 at apressure ranging, for example, from substantially atmospheric to 1000pounds or more per square inch is directed through line I8 and valve I1and, in accordance with the objects of the invention, is commingled witha cooler stream of hydrocarbon oil introduced in the manner to bedescribed later in order to quench the stream of hot oil to atemperature ranging, for example, from 400 to 800 F., and the resultingmixture of conversion products, cooling oil, and catalyst is supplied tovaporizing and separating chamber I8. Chamber I8 is preferably operatedat a reduced pressure relative to that employed on the outlet of heatingcoil I4 ranging, for example, from substantially atmospheric to 400pounds or more per square inch whereby to separate vaporous conversionproducts from the liquid conversion products and catalyst. Preferablyalso, cooling oil is supplied to chamber I8-in the manner tobe describedlater in order to adjust the viscosity and gravity of the heavy oilremoved with the catalyst from the bottom of chamber I8 and to controlthe end point of the vaporous conversion products separated in chamberI8.

When desired, chamber I8 may be operated as a catalyst separatingchamber wherein the catalyst is reduced to a substantially dry powdercontaining a high proportion of carbonaceous materials formed byreducing the liquid residue to a substantially dry coke. In such cases,however. it would be desirable to employ more than one chamber in orderthat one or more of the chambers may be .cleaned while-other or othersare employed in the conversion-treatment. In this type of operation thecatalyst is removed as ya substantially dry powder containing a. highproportion of carbonaceous material and may be supplied to a catalystregenerating system, not

shown in the drawing, to prepare the catalyst for reuse.

In the preferred treatment, however, the liquid hydrocarbons andcatalyst separated inV chamber I8 are removed therefrom by way of lineI9 and may be directed through valve 20 and recovered in this form forseparation of the catalyst and oil in a system not included in theprocess. Preferably, however, the catalyst and oil in line I9 aredirected through line 2l and valve 22 into catalyst separating chamber23 wherein the mixture is allowed to settle into two parts, thecarbonized or spent catalyst being of a greater particle size willsettle with the heavy hydrocarbon oil while the relatively cleancatalyst will remain in suspension in the light oil. When desired, ahydrocarbon solvent, such as light reux con'- densate, gasoline, orkerosene, or any light hydrocarbon oil formed in the process, or a lighthydrocarbon oil introduced from an external source supplied by way ofline 24 and valve 25, may be commingled with the stream of hydrocarbonoilv and catalyst in line 22 in order to reduce the viscosity andgravity thereof to thus serve as a diluent during the vsettlingoperation.

The heavy oil and spent catalyst separated in chamber 23 is removedtherefrom by way of line 28 and valve 21 and recovered orV subjected toany desired further treatment to revivify the catalyst. The lighterportion of the hydrocarbon oil and relatively clean catalyst separatedin chamber 23 are removed therefrom by way of line 28 and directedthrough valve 29 to pump 30, which discharges through line 3| and valve32 into line 58, commingling therein with the light reflux condensateand catalyst supplied to heating coil I4 for treatment in the mannerpreviously described.

The vaporous conversion products separated in chamber I8 are removedtherefrom by way of line 33 and directed through valve 34 into line II,commingling therein with the vapors removed from chamber 8, whichmixture is supplied to fractionator I3. Fractionator I3 and thecopdensing and receiving equipment in communication therewith arepreferably operated at a superatmospheric pressure of the same order asthat employed in chambers 8 and I8. Simulta- `neously with theintroduction of the vaporous 11, which discharges the charging outhrough line Il and valve Il into fractionator Il.

The charging oil and vaporous products supplied to fractionator Il arefractionated therein of the vapors and charging oil being condensed' andcollected as light and heavylreiiux condensates. Fractionated vaporsseparated in fractionator Il are directed through line 4l and valve 4Ito cooling and condensation in condenser 42. Distillate, together withundissolved and uncon-` densed gases from condenser 42, is directedthrough line 4I and valve 44-into receiver 45 wherein the distillate andgases are collectedand separated. Normally gaseous'products collectedand separated in receiver 45 are removed therefrom by wayof line 4E andvalve "and recovered as a product of the process or subjected to anydesired further-treatment. Theportion of the distillate collected andseparated in receiver 45 may be returned to the upper `portion ofiractionator I 3 to serve as a reiluxing and cooling meg dium while theresidual portion thereof may be been found to be effective in thecraklng treatment oi' hydrocarbon vapors.

Although, the catalysts above recited are generally considered to be thepreferred catalysts. their use is not to be construed as a limitingteature, for various other catalysts well `known to those in the art maybe employed within the broad scope of the invention.

An example of one specific operation of the process as it may beemployed in an apparatus such as illustrated and above described isapproximately as follows: Heavy reflux condensate removed from receiver45 by way of line 48 and rated within fractionator I3 is removedtherefrom by way of line 50 and is directed through valve 5I to pump 52,which discharges through line 53 and valve 54 into heating coil I, theheavy reilux condensate being subjected to treatment as previouslydescribed.

Light reux condensate separated in fraction-l ator I3 is directedthrough line 55 and valve to pump 51. Pump 51 discharges through line 58and a portion is directed through line 59 and valve 60 into line I6 toserve as a quenching oil 'as previously described. Another portion, whendesired. may be directed' through lines' 59 and 6I and valve 82 into theupper portion of chamber I8 to serve as a cooling` medium therein. Still'another portion thereof may be removed from the system by way of line63 and valve 64 for use in preparing the catalyst slurry' in themanner/to be described later or for use as the hydrocarbon solvent whichis mixedwith the oil and catalyst in line 2| as previously described.The yresidual portion/of the light reilux condensate in line 58 isdirected through valve 85 and is commingled with a slurry of crackingcatalyst prepared in the manner to be described later and the mixturesupplied to heating coil I4 for treatment as previously described.

The catalyst slurry comprising, for example, a mixture of powderedcracking catalyst and light retiux condensate orl any relativelylighthydrocarbon oil of characteristics similar to those ot the lightreiiux condensate is supplied to the system by way of line 66 and isdirected through formed in the manner to be described later is subjectedto pyrolytic cracking In a heating coil and communicating reactionchamber at a temperature oi 940 F. and at a superatmospheric pressure of20 pounds per square inch. The resulting conversion products aresupplied to a densate to which approximately 2% of a powderedsilica-alumina catalyst is added is supplied to a heating coil andheated therein to a temperature of approximately 980 F. and-at asuperatmospheric pressure of approximately 50 pounds per square inch.The heated stream of conversion products containing the suspendedpowdered arating chamber wherein the mixture is separated into twoparts, one part comprising essentially a heavy residual oil and spentcatalyst and the second part the lighter oil and relatively cleancatalyst. The rst part is removed and subi ected to any well knowntreatment for revivivalve 61 to pump i8 which discharges through f yline69 and valve 10 into line 58, commingling therein with the light refluxcondensate as previously described.

Catalysts which have been found to be effective in the catalyticcracking of hydrocarbon oils may comprise, for example, powder orgranules of silica or other silicious and refractory materialscomposited with compounds selected from the group consisting of alumina,zirconia, vanadia, and thoria. In addition, the hydrosilicates ofalumina,l acid treated clays, or the like. have also heavy reuxcondensates.

ilcation of the spent catalyst while the second part is returned to thecatalytic conversion step.

The catalytic and pyrolytlc conversin products are fractionated'togetherwith the charging oil, the latter comprising a 24 A. P. I. gravity Mid-Continent reduced crude oil. In the fractionation fractionated vapors ofapproximately 400 end point are separated from the higher boilingconversion products and higher boiling portions of the charge. Thefractionated vapors are subjected to cooling and condensation and theresulting distillate and gas separately recovered. The higher boilingconversion products and heavier portions of the charge are condensed andseparated in the fractionating zone as light and The light reuxcondensate is supplied to the catalytic conversion step and the heavyreflux condensate to the pyrolytic conversion step.

When employing conditions as above described. this operation will yieldapproximately 55% of 400 end point gasoline of 76 octane number,approximately 34% of liquid residue, the balance being principally gasand loss. I

I claim as my invention:

l. In a hydrocarbon oil selective cracking process wherein vaporousconversion products formed in the process are separated by fractionationinto 4fractionated vapors boiling in the range oi' gasos;` line andlight and heavy reflux condensates, saidl heavy reilux condensatesubjected to pyrolytic conversion, said light reilux condensatesubjected to catalytic conversion and the conversion products from bothfractionated as aforesaid, the improvement which comprises accomplishingsaid. 'catalytic conversion by commingling said light reassenso productsto a vaporizing and separating cham- 4 to separate fractionated vaporsboiling in the range of gasoline from the higher boiling conversionproducts and charging oil, recovering said fractionated vapors,condensing said higher boiling conversion products and charging oil aslight and heavy reux condensates, supplying said heavy reux condensateto the pyrolytic conversion treatment as said relatively heavy oil,supthe cracking reaction by commingling therewith afstream of colderoil. supplying the mixture of cooling oil, conversion products, andcatalyst to a vaporizin-g and separating chamber wherein vaporoushydrocarbons are separated from theY liquid hydrocarbons and catalyst,subjecting said vaporous hydrocarbons to fractionation in commingledstate With the pyrolytic vaporous conversion products; supplying saidliquid hydrocarbons and catalyst to a catalyst separating chamberwherein they are separated into two parts. one part consistingessentially of the heavy liquid hydrocarbons and s nt catalyst and thesecond part of the lighter/liquid hydrocarbons and relatively cleancatalyst, recovering the nrst part and returning the second part to thecatalytic conversion step. .s

2. The process deiined in claim .l further. characterized in that the"quenching oil consists essentially of a portion of the light reiluxcondensate formed in the process.

3. A process for the production of motor fuel, which compriseslsubjecting arelatively heavy oil to pyrolytic cracking, separating theresulting conversion products into pyrolytic vaporous conversionproducts and non-vaporous liquid residue,

simultaneously therewith commingling a relatively light hydrocarbon o ilwith powdered cracking Y catalyst to form a slurry. supplying theresulting slurry to a reaction zone wherein it is heated to e a.conversion. temperature, quenching the stream ofhot oil and catalystleaving said reaction zone suillciently to arrest the cracking reaction-by commingling therewith a colder stream of hydrocarbon oil, supplyingtheresulting vmixture of cooling oil, catalyst, and lcatalyticconversion plyng at least a portion of said light reflux condensate tothe catalytic conversion step as said relatively light hydrocarbon oil.supplying the liquid hydrocarbons and catalyst removed from the secondmentioned vaporizlng and separating chamber to a catalyst separatingchamber wherein the mixture is separated into two parts, one partconsisting essentially of the heavy liquid hydrocarbons and spentcatalyst which is recovered and the second part consisting essentiallyof the light hydrocarbons and relatively clean catalyst which isreturned to the catalytic conversion step.

fi. The process dened in claim 3 further characterized in that a portionof the light reflux condensate is commingled with the stream of hot oilandcatalyst as the quenching oil.

5. The process defined in claim 3 further characterized in that aportion of the light redux condensate is supplied to the vaporizing andseparating chamber to control the gravity and viscosity of the liquidhydrocarbons removed with the catalyst from the lower portion-thereof.

6. A hydrocarbon oil conversion process which comprises subjecting theoil to catalytic conversion conditions in admixture with a powderedcatalyst, separating resultant vapors from liquid conversion productscontaining the powdered catalyst, separating the catalyst-containingliquid into two parts, one comprising heavy hydrocarbons andsubstantially spent catalyst particles and the other comprising lighterhydrocarbons and cleaner catalyst particles, withdrawing theiirst-mentioned part from the process and returning the second-mentionedpart tothe catalytic conversion step.

